The series closely follows the plot of the novel, which, like many of Pratchett's novels it introduces an element of modern society into the magical and vaguely late medieval, early modern world of the Disc, in this case Rock and Roll music and stardom, with nearly disastrous consequences. It also introduces Susan Sto Helit, daughter of Mort and Ysabell and granddaughter of Death. The series takes the association of the "Band with Rocks In" with the Beatles even further than the book does, evolving their style from 1950s rock and early 1960s beat music (and mixing-bowl haircuts) in Ankh-Morpork, to acid rock in Scrote, to spiritual hippie rock in Quirm. In Sto Lat, they sound like the Jimi Hendrix Experience or Bad Company, but are dressed in clothes similar to the Beatles on the cover of the Sgt. Pepper's Lonely Hearts Club Band album.